

A003094


Number of unlabeled connected planar simple graphs with n nodes.
(Formerly M1652)


20



1, 1, 1, 2, 6, 20, 99, 646, 5974, 71885, 1052805, 17449299, 313372298
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,4


COMMENTS

Inverse Euler transform of A005470.  Christian G. Bower, May 16 2003


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
R. J. Wilson, Introduction to Graph Theory. Academic Press, NY, 1972, p. 162.


LINKS

David Wasserman and Brendan McKay, Table of n, a(n) for n = 0..12
E. Friedman, Illustration of small graphs
N. J. A. Sloane, Transforms
Peter Steinbach, Field Guide to Simple Graphs, Volume 1, Part 17 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.)
Eric Weisstein's World of Mathematics, Planar Connected Graph


EXAMPLE

a(3) = 2 since the path ooo and the triangle are the two connected planar simple graphs on three nodes.


CROSSREFS

Cf. A005470, A126201.
Sequence in context: A020095 A026991 A049379 * A073964 A079457 A079455
Adjacent sequences: A003091 A003092 A003093 * A003095 A003096 A003097


KEYWORD

nonn,nice,hard,more,core


AUTHOR

N. J. A. Sloane


EXTENSIONS

More terms from Brendan McKay
a(12) added by Brendan McKay, Dec 06 2014


STATUS

approved



